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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 HQHWRIzI8d1D/yjgUH6hbbrucRckztCWmykXexpPuQzuOJc8SU09x/zigL8A9vPI
 pldjfJmqXG633WBLMA3QuA==

<SEC-DOCUMENT>0001140361-07-006535.txt : 20070329
<SEC-HEADER>0001140361-07-006535.hdr.sgml : 20070329
<ACCEPTANCE-DATETIME>20070329161611
ACCESSION NUMBER:		0001140361-07-006535
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070329
FILED AS OF DATE:		20070329
DATE AS OF CHANGE:		20070329

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Flagstone Reinsurance Holdings Ltd
		CENTRAL INDEX KEY:			0001347815
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				000000000

	BUSINESS ADDRESS:	
		STREET 1:		CRAWFORD HOUSE 23 CHURCH ST
		CITY:			HAMILTON BERMUDA HM 11
		STATE:			D0
		ZIP:			00000

	MAIL ADDRESS:	
		STREET 1:		CRAWFORD HOUSE 23 CHURCH ST
		CITY:			HAMILTON BERMUDA HM 11
		STATE:			D0
		ZIP:			00000

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			JAMES E DANIEL
		CENTRAL INDEX KEY:			0001241077

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33364
		FILM NUMBER:		07727843

	MAIL ADDRESS:	
		STREET 1:		4909 S E INTERNATIONAL WAY
		CITY:			PORTLAND
		STATE:			OR
		ZIP:			97222

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LEHMAN BROTHERS HOLDINGS INC
		CENTRAL INDEX KEY:			0000806085
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1130

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33364
		FILM NUMBER:		07727844

	BUSINESS ADDRESS:	
		STREET 1:		LEHMAN BROTHERS
		STREET 2:		745 SEVENTH AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		2125267000

	MAIL ADDRESS:	
		STREET 1:		LEHMAN BROTHERS
		STREET 2:		745 SEVENTH AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

	FORMER NAME:	
		FORMER CONFORMED NAME:	SHEARSON LEHMAN HUTTON HOLDINGS INC
		DATE OF NAME CHANGE:	19901017
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2007-03-29</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001347815</issuerCik>
        <issuerName>Flagstone Reinsurance Holdings Ltd</issuerName>
        <issuerTradingSymbol>N/A</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000806085</rptOwnerCik>
            <rptOwnerName>LEHMAN BROTHERS HOLDINGS INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>745 SEVENTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001241077</rptOwnerCik>
            <rptOwnerName>JAMES E DANIEL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>CRAWFORD HOUSE 23 CHURCH ST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HAMILTON</rptOwnerCity>
            <rptOwnerState>D0</rptOwnerState>
            <rptOwnerZipCode>00000</rptOwnerZipCode>
            <rptOwnerStateDescription>BERMUDA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15830000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5833</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">By indirect, wholly-owned subsidiaries of the Reporting Person: 5,117,509 shares held by Lehman Brothers Merchant Banking Partners III L.P.; 1,127,932 held by Lehman Brothers Merchant Banking Fund III L.P; 1,359,223 held by Lehman Brothers Merchant Banking Fund (B) III L.P.; 2,147,199 held by LB I Group Inc.; 172,182 held by Lehman Brothers Co-Investment Capital Partners L.P.; 122,082 held by Lehman Brothers Co-Investment Group L.P.; 4,705,737 held by Lehman Brothers Co-Investment Partners L.P.; 430,000 held by Lehman Brothers Fund of Funds XVIII-Co-Investment Holdings, L.P.; 248,137 held by Lehman Brothers Merchant Banking Capital Partners V L.P.; and 400,000 held by Lehman Crossroads Series XVII Master Holding Fund 66, L.P.</footnote>
        <footnote id="F2">Mr. James is a director of the Issuer and a Managing Director of Lehman Brothers Inc. (&quot;LBI&quot;), a wholly-owned subsidiary of Lehman Brothers Holdings Inc.(&quot;LBHI&quot;). Under the terms of Mr. James' employment with LBI, LBI is the beneficial owner of the 5,833 shares of Common Stock granted to Mr. James as a director of the Issuer.  LBHI may be deemed to be the beneficial owner of these shares of Common Stock. Mr. James disclaims beneficial ownership of these shares of Common Stock and the other shares of Common Stock reported herein.</footnote>
    </footnotes>

    <remarks>JOINT FILER INFORMATION

Title of Securities: Common Stock
Issuer &amp;  Ticker Symbol: Flagstone Reinsurance Holdings Limited
Designated Filer: Lehman Brothers Holdings Inc.
745 Seventh Avenue
New York, New York 10019
Other Joint Filer:
Daniel James
C/O Flagstone Reinsurance Holdings Limited
CRAWFORD HOUSE 23 CHURCH ST
HAMILTON BERMUDA HM D0 00000
Date of Event Requiring Statement:
March 29, 2007
Signature on behalf of other joint filer:
/s/ Daniel James</remarks>

    <ownerSignature>
        <signatureName>/s/ Barrett S. DiPaolo</signatureName>
        <signatureDate>2007-03-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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